clearly, president obama feels the weight of the moment. no american can relive the horror of this. >> we can't tolerate this anymore. these tragedies must end. and to end them, we must change. we will be told that the causes of such violence are complex and that is true. no single law, no set of laws can eliminate evil from the world or prevent every senseless act of violence in our society. but that can't be an excuse for an action. surely, we can do better than this. >> this is a moment in history where an event alters the direction of a country and moves lawmakers to unity. diane feinstein was the first to announce an update on an assault weapons ban which she introduced in congress and will introduce it early next year. >> i intend to introduce a bill. and i intend one way or another, no matter how long it takes, to get that bill through. there's one thing i'm sure of. that in the absence of doing something, that is sound, that is practical, that is workable, these incidents are not going to stop. i've watched them now since the texas